NEWTOWN -- The investigation report on the Sandy Hook Elementary School massacre won't be available in June as expected, state officials confirmed Wednesday.

Danbury State's Attorney Stephen Sedensky said Wednesday the report may not be available until September or later, but declined to provide details on what elements still need to be completed.

"I can't be specific on that, but the State Police are working hard on the case," he said. "It's more important for us to get it done right than fast."

Irving Pinsky, a lawyer who represents several families affected by the shootings, said he is concerned about the delay and what information state officials may be trying to hold back from the public.

"It's as though they are feeding the conspiracy theorists more fodder," he said. "It's really sad that we can't get the information on this case that we have the right to."

He added that delays in releasing the report could complicate efforts of some families to file legal proceedings because of fast-approaching legal deadlines.

"It really depends on what information they are holding back," Pinsky said.

The report will concern the events of Dec. 14, when Adam Lanza shot and killed his mother, Nancy Lanza, in her bedroom before going to Sandy Hook Elementary School, where he killed 20 first-graders and six educators and then turned a gun on himself.

Sedensky rebuffed claims that the report is being delayed, noting that he told state legislators in January that "we are hoping for this summer, perhaps in June, but that's certainly subject to change."

A state police spokesman said the June deadline was "never etched in stone."

"There are many things that still have to come together," said Lt. J. Paul Vance. "We are leaving no stone unturned."

Vance added that the report will be ready, "when all the work is done, when we've covered every base and done everything we can."

He added that when the report is completed, police officials will sit down with the officials from the state's attorney's office and relatives of those slain to review the material before it is released to the public.

State police officials were criticized in March over reports that details of Adam Lanza's plans, including a large spreadsheet of mass shootings, were revealed in police-related seminars in New Orleans, Las Vegas and at Foxwoods in Connecticut.

Shortly after that, officials released the search warrant affidavits for the Lanza home in Sandy Hook, and two vehicles. It's the only investigative information that's been released to date in the Dec. 14 tragedy.